Julian (d. 363) may not have been perfect, but he had more than his share of detractors, especially among Christian writers of the period who were upset by his apostasy.
Gregory Nanzienzen (330-390) blasts him in the following in a translation from 1888:1. "HEAR me all ye nations, give ear unto me all ye dwellers upon earth," for I am calling on you all, as it were, from a conspicuous and lofty watch-tower, with a cry both high and loud. Hear ye nations, tribes, tongues, every kind of men, and every age, as many as now are, and as many as shall be; and in order that my proclamation may be greater, every Power of heaven, all ye Angels, whose deed was the putting down of the tyrant, who have overthrown not Sihon, king of the Amorites, nor Og, king of Bashan -- insignificant princes, and injuring but a small part the land of Israel -- but the Dragon, the Apostate, the Great Mind, the Assyrian, the public and private enemy of all in common, him that has madly raged and threatened much upon earth, and that has spoken and meditated much unrighteousness against Heaven!
Gregory Nazianzen, "Julian the Emperor" (1888). Oration 4: First Invective Against Julian.
Not that Gregory Nanzienzen does so, but Ammianus Marcellinus (4th century historian who was with Julian in Persia) says Julian should not be faulted with starting the war against the Sassanid Persians.
Book XXV Ch. IV
23. And since his detractors have accused him of provoking new wars, to the injury of the commonwealth, let them know the unquestionable truth, that it was not Julian but Constantius who occasioned the hostility of the Parthians by greedily acquiescing in the falsehoods of Metrodorus, as we have already set forth.
24. In consequence of this conduct our armies were slain, numbers of our soldiers were taken prisoners, cities were rased, fortresses were stormed and destroyed, provinces were exhausted by heavy expenses, and in short the Persians, putting their threats into effect, were led to seek to become masters of everything up to Bithynia and the shores of the Propontis.
25. While the Gallic wars grew more and more violent, the Germans overrunning our territories, and being on the point of forcing the passes of the Alps in order to invade Italy, there was nothing to be seen but tears and consternation, the recollection of the past being bitter, the expectation of the future still more woeful. All these miseries, this youth, being sent into the West with the rank of Caesar, put an end to with marvellous celerity, treating the kings of those countries as base-born slaves.
26. Then in order to re-establish the prosperity of the east, with similar energy he attacked the Persians, and would have gained in that country both a triumph and a surname, if the will of heaven had been in accordance with his glorious plans and actions.
27. And as we know by experience that some men are so rash and hasty that if conquered they return to battle, if shipwrecked, to the sea, in short, each to the difficulties by which he has been frequently overcome, so some find fault with this emperor for returning to similar exploit: after having been repeatedly victorious.Source:
The Roman History of Ammianus Marcellinus, During the Reign of the Emperors Constantius, Julian, Jovianus, Valentinian, and Valens, Translated by C.D. Yonge; (1902).
